Viticulture Flashcards
What are the 2 main species of vine?
Vitis vinifera
North American Vines (3 chief species):
Vitis labrusca
Vitis riparia
Vitis rupestris
What is phylloxera?
A fungal disease A viral disease A North American root louse
A North American root louse.
Of the two main vine species, which one is more resistant to phylloxera?
How does it protect itself?
North American vine species are more resistant to phylloxera. It is for this reason American rootstocks are widely used across the world.
The North American vine protects itself from phylloxera by seeping a sticky sap that inhibits the louse from eating, and the vine generates a defensive layer behind a wound which prevents the louse from damaging the plant material further.
Are there any places in the world today that remain free of phylloxera?
Yes, the major ones are:
Chile Some areas in South Australia and Argentina
Of the two main vine species, which one is the most widely used around the world for quality wine production?
Vitis vinifera is most used for fine wine grape growing in the world.
The grape varieties we all know by name are from the Vitis vinifera family, such as Sauvignon Blanc, Chardonnay, Pinot Noir, Zinfandel, Syrah, and Cabernet Sauvignon.
What are some primary differences between Vitis vinifera and North American vines?
Vitis vinifera:
known to have more desirable aromas for wine considered to produce higher-quality grapes for the production of fine wine
North American vines:
more resistant to pests and diseases than vinifera generally better suited to extreme climates than vinifera
What are 2 different ways a vine can be propagated?
Cutting - when a section of a shoot is cut off from an existing vine and is planted in order to grow a brand new plant. It’s done mostly in nurseries;
Layering: A vine’s 1 year-old cane is bent into the ground and partially buried with the tip of the cane poking out above ground; the buried part grows roots and establishes itself as a new plant. It takes place in the vineyard.
What is clonal selection?
When a vine naturally mutates and its new, positive characteristics are propagated by cutting or layering.
Explain grafting.
Grafting is a procedure used to fuse budwood of a desired variety (usually V. vinifera) onto another rootstock (usually a North American vine).
This technique was discovered to be both useful and necessary after phylloxera decimated European vineyards in the mid-to-late 1800s. The idea is to have a phylloxera-resistant vine that produces V. vinifera.
What are some of the benefits of grafting onto American rootstocks?
What are some of the benefits of grafting onto American rootstocks?
What is head grafting and why is it used?
Head grafting is when a vine’s top, or head, is cut off its trunk and the cutting of a new variety is grafted on to the trunk where the old head was.
The purpose of head grafting is to switch out grape varieties instead of uprooting and replanting an entire vineyard. Head grafting will produce fruit the year after the grafting, and it’s a lot less expensive than replanting an entire vineyard with the added bonus of keeping the established trunk and roots.
How are new grape varieties created?
Cross-fertilization
What is cross-fertilization?
Name a few reasons why a viticulturist might want to cross-fertilize.
Cross-fertilization is when a viticulturist takes the pollen from the male part of one vine’s flowers and fertilizes the female parts of a different vine’s flowers to create a new grape variety.
The cross-fertilized flowers will grow into grapes, which will have seeds. Those seeds are collected, later planted, and if those seeds grow into a viable plant, a new grape variety is born.
Reasons to cross-fertilize:
To create a disease resistant variety; To adapt the new grape to climate extremes or drought; To increase quality or yields.
What is the difference between crossings and hybrids?
Crossings: when a new grape variety is created by crossing parents of the same vine species, e.g. Cabernet Sauvignon (Sauvignon Blanc x Cabernet Franc - both V. vinifera).
Hybrids: when at least two different vine species, usually a North American vine and a vinifera vine, are crossed to create a brand new vine species, e.g. Concord and Vidal Blanc (only 1 parent is V. vinifera).
What is the crossing of Cabernet Sauvignon?
Cabernet Franc x Sauvignon Blanc
What is the crossing of Müller-Thurgau?
Riesling x Madeleine Royale
What is the crossing of Pinotage?
Roots
Permanent wood
1 year-old wood
Green parts (also known as the canopy: leaves, grapes, tendrils, etc.)
Explain the importance of a vine’s leaves.
Leaves are what drive the plant’s growth.
Via photosynthesis, leaves use sunshine to convert water and CO2 into the things it needs to grow: glucose and oxygen.
What is transpiration?
Transpiration is the process of how water is absorbed by a vine’s roots, transported throughout the plant, and out of its leaves in vapor form.
The warmer the climate, the faster water evaporates from the leaves, which means the vine needs more water from the soil.
What are tendrils on a vine and what is their role?
Tendrils are a vine’s support system so that it stays upright (or attached to a trellising system).
What are the buds on a vine?
Where are they found?
Buds contain and will become the following year’s green parts (tendrils, flowers, leaves, shoot).
Buds are primordial shoots found between a shoot and a leaf.
What is 1-year-old wood (aka a cane)?
The previous year’s shoot
The buds on last year’s shoot will be the 1-year-old wood’s shoots, tendrils, and leaves.
What is permanent wood on a vine?
Wood that is more than 1 year old:
trunk arms / cordons (if there)
What are the functions of a vine’s roots?
Absorb water + nutrients which they send up the plant
Anchor the vine in the soil
Store carbohydrates over winter to keep the vine alive
What are the “reproductive organs” of a vine?
Flowers
Flowers have both male and female parts, and vines’ flowers self-pollinate. Each pollinated flower then turns into a grape.
What is inflorescence?
Clusters of flowers (before they actually become flowers).
Inflorescences will eventually become flowers which then transform into grape clusters.
What is the difference between a cane and spur?
They’re both 1 year-old wood from the previous year’s growth. However, the main difference between them is how many buds each has.
Cane: a long woody branch with 8 to 20 buds
Spur: a short woody branch with only 2 to 3 buds
What are some important factors to consider when deciding where to establish a new vineyard?
Environmental/Climate considerations
location and aspect of proposed vineyard
soil type/fertility, drainage, average sunlight/rain, temperature
Trade/Business considerations
how remote is the vineyard?
how easy will it be to find employees or help at harvest?
Which grape(s) to plant?
which varieties suit the climate?
is there demand for the grape(s)?
any legal restrictions?
What are the 2 main types of vine training?
Head training
Cordon training
Describe head training.
Usually just a trunk (not a lot of other permanent wood)
Some have just a few short “arms” of permanent wood growing out of the top of the trunk
Describe cordon training.
More permanent wood than head trained;
A trunk with usually one or two permanent arms or “cordons”;
Usually spur-pruned (spurs look like “fingers” growing out of the arm/cordon, see photo);
Mechanized harvesting easier.
Define pruning.
The removal of undesirable canes, leaves, and permanent wood.
When are vines pruned?
Winter
Summer
What are the purposes of summer pruning?
Control the canopy, which…
Forces sugar production in the grape instead of the vine directing that energy to expand the canopy;
Give grapes favorable sun exposure via leaf stripping.
In regions with powerful sunlight, what risk is there if the canopy is deleafed too much during summer pruning and exposing the grapes to that intense sunlight?
Sun burn, which will lead to off-flavors
What are the purposes of winter pruning?
To choose the number + location of buds that will form shoots in the upcoming growing season;
Ensure buds are not too close to each other (this helps with next year’s canopy management).
What are the 2 styles of winter pruning?
Spur
Replacement cane
Spur pruning can be found on what type of vine training?:
Head trained Cordon trained Both head and cordon trained
Both head and cordon trained
Replacement cane pruning is most often found on what type of vine training?:
Head trained Cordon trained Both head and cordon trained
Head trained
What are trellises, or a trellising system?
A system of permanent stakes (wood or metal) with wires that support the vine for its annual and seasonal growth.
The wires can also support canes and cordons.
3 reasons to use a trellising system instead of Bush vines:
Control the amount of sunlight that gets into the canopy;
Improve air circulation for the leaves and grapes;
Positioning grapes and leaves improve mechanical harvesting + distribution of any sprays used.
Give 2 examples of head-trained vines.
Guyot
Bush
Bush (‘untrellised’) vines tend to produce a lush canopy, so they perform best in hot, dry regions such as Jérèz or Southern Rhône where the grapes need the extra shade.
Bush vines are generally head-trained and spur-pruned (meaning, 2-4 buds on each 1 year-old spur).
Guyot vines are generally head-trained and cane-pruned (meaning, a permanent main trunk with 1 cane + a spur [Single Guyot) or 2 canes + spurs [Double Guyot]).
What is a synonym for Bush vines?
Gobelet – so called as it resembles the shape of a wine glass or goblet.
Bush/Gobelet vines are untrellised.
When using replacement cane pruning, if the vine has 1 cane it’s called ______ Guyot; if it has 2 canes it’s called ______ Guyot.
1 cane = Single Guyot
2 canes = Double Guyot
What is the most widely used trellising system?
Vertical shoot positioning (VPS)
Describe Vertical Shoot Positioning (VSP).
How is it beneficial?
Which pruning styles is it compatible with?
VPS is where shoots are positioned in an upward position attached to the treillis wires, creating a single-layered, narrow canopy.
VPS allows for good air circulation and the grapes to be exposed to direct sunlight (less shade).
Compatible with both replacement cane pruning and spur-pruning
What types of pruning can VSP be used with?
Cane- or spur- pruned wines
VSP is conducive to which type of harvesting: mechanical or hand?
mechanical
Define planting density.
the number of vines planted within a determined area
How is planting density typically conveyed?
Number of vines per ha.
The average in Burgundy is 8,000 to 10,000
How big is a hectare?
A square stretch of land that has 100-meter sides
1 acre is approximately how many hectares?
1 acre = 0.4ha
1 ha = 2.47 acres
What are 2 big factors that help a grape grower determine a vineyard’s planting density?
Availability of WATER and NUTRIENTS
If a region has good water availability + soil with just-enough nutrients, would it make sense that a vineyard’s planting density be higher or lower?
Higher because wwith all that water available, vines will produce a profuse canpy.
Higher density planting increases competition which will curb the vine’s tendency to put all the energy into the canopy..
This where winter pruning comes in: did the grower leave the proper number of buds from the previous year growth to control canopy and fruit development this year?
Which soil is more desirable for viticulture:
barely fertile very fertile
Barely fertile.
Stressed vines make good wines. Very fertile soils make vines grow like crazy and a challenge to manage, even with super-high density plantings.
What does yield measure?
How is yield expressed?
Yield measures the quantity of grapes produced, in weight (tonnes per hectare) or volume (hectolitres per hectare)
Explain véraison.
Veraison is the onset of ripening and when the grapes change color:
- red varieties turn from green to purple or black,
- white varieties go from green to translucent-pink and gold.
What happens to grapes during berry ripening?
Sugars increase
Acidity levels increase
Tannins develop and become less astringent.
What is green harvesting and when is it done?
Why is it done?
Dropping underdeveloped grape clusters right after veraison.
Viticulturists walk the vineyard and cut off immature grape clusters, leaving them on the ground.
It is done if yields are going to be too high.
How does the vine react if green harvesting is done at the wrong time?
The vine increases the size of the berries on teh remaining clusters, which can dilute flavors and increase yields (in weight / volume)
Name some vineyard pests other than phylloxera.
Birds
Dees and other mammals
Nematodes
Insects
What are nematodes, and what damage can they cause to a vine?
nematodes are microscopic worns that attack a vine’s roots, leaving open wounds which interfere with water and nutrients uptake and though which viruses are known to enter.
Affected wines must be removed, they can’t be grafted
What protections for their vines can a grape grower utilize against birds and mammals?
Netting for birds
Fencing for mammals
What damage can insects cause to vines?
They can eat through leaves and grapes, the latter of which can invite rot and disease.
Leaf damage slow photosynthesis, which directly affects a vine’s ability to ripen its grapes.
What are the 3 types of diseases that affect vines?
Fungal
Viral
Bacterial
Name 3 fungal diseases.
Downy Mildew
Powdery Mildew
Grey rot
What parts of the vine do Downy or Powdery Mildew affect?
All green parts of the vine and the grapes can be affected.
What is the typical fungicide treatment for Powdery Mildew?
Sulfur-based spray
What is the typical fungicide treatment for Downy Mildew?
Bordeaux mixture, a copper-based spray
In what climate will you find more fungicide treatments used?
Why?
Maritime
High rainfall and generally more humid air encourage fungi
How are fungal diseases controlled?
fungicides
What are the treatments or cures for viral diseases?
None.
The only way to get rid of a viral disease is to uproot the vines and sanitize the land
How do viruses spread in vines?
Nematodes
Cuttings
How do viruses affect vines?
Can they kill the vine?
They reduce both quality and yield.
Most viral diseases do not kill the vine.
What is the fungus that causes grey rot?
BOTRYTIS CINEREA is the fungus that creates grey rot.
Which one develops (the beneficial Botrytis or the bad grey rot) depends on the weather. If afetrnoons become sunny and warm, dissipating humidity and moisture in the air, Botrytis develops. If afternoons remain grey and soggy, grey rot takes hold and rots the grapes.
How do bacterial diseases affect vines?
Can bacterial diseases kill a vine?
Reduce both grape quality and yield.
SOme bacterial diseases can kill the vine.
How do bacterial diseases spread in vines?
Insectes called sharpshooters spread bacterial diseases.
What are the treatments or cures for bacterial diseases?
None. The vine must be uprotted and the land sanitized.
If the vine is infected by a sharpshooter, the grower can try to disrupt the insect’s lifecycle with quarantine and other methods but it is difficult.
Describe sustainable agriculture.
Use of synthetic chemicals is restricted but not prohibited.
Spraying or applying chemicals only when needed.
Practising Integrated Pest Management - introducing natural predators to control pests.
Create biodiversity in the vineyard.
Describe organic viticulture.
Use of synthetic chemicals is not allowed.
The only real chemicals allowed are sulfur and copper and their application is restricted.
If a winery wants to be certified organic, they must apply for accreditation with one of the certifying bodies and work with their vineyard organically for at least 2 years or more prior to certification.
Describe biodynamic agriculture.
Biodynaic is much more than a method, it’s a spiritual science, a belief system, a HOLISTIC WAY OF SEEING AND UNDERSTANDING THE NATURAL WORLD THAT FOCUSES ON GENERAL PRACTICES.
Biodynamics sees the vineyard as AN ECOLOGICAL WHOLE: not just rows of grapevines but the soil beneath them, the flora and fauna in the area, growing together interdependently.
B differs from organic or sustainable agriculture in its idea that farming can be attuned to spiritual forces of the cosmos. This might mean linking sowing and harvesting to the pahses of the moon or the positions of the planets.
Who are seen as the father and mother of biodynamics?
Rudolf STeiner and Maria Thun
What are the homeopathic remedies called in biodynamics used to fertilize soil and protect vines?
Preparations
What are the top three most important nutrients for vines?
Nitrogen, phosphorus, potassium.
They are all naturally present in the soil.
What is chlorosis?
Clorosis is a nutrient deficiency in the soil that affects the vine’s ability to photosynthesis. SIgn of C is yellow leaves and poor overall growth.
The usual cause for C is a lack of iron in the soil. Farmers can add iron-rich fertilizers or plant iron-producing grasses as cover crops to treat the soil.
List a vine’s annual cycle.
BUDBURST: early spring
FIRST SHOOT / LEF GROTH: spring
FLOWERING: late spring / early summer
FRUIT SET: early summer
VERAISON: summer
RIPENING: summer / late summer
HARVEST: late summer / early autumn
DORMANCY: winter
After winter, when temperatures rise above 10°C (50°F) is when vines start _____.
When the temperature drops below 10°C is when vines go _____.
BUDBURST
DORMANT
When does budburst happen in each hemisphere?
What happens during budburst?
March-April (early spring): northern hemisphere
Sept-Oct (early spring): southern hemisphere
New growth starts emerging from buds
During what months does flowering occur in the northern and southern hemispheres?
Mary-June: northern hemisphere
Nov-Dec: southern hemisphere
What is the optimal weather during flowering?
Warm temperatures, plenty of sunshine, little or no rain
What is coulure?
When a flower does not turn into a berry:
lack of self-polination
too much wind which blows pollen away
wet / rainy events that cause the flower caps to stick
physiological reasons.
The unfertilzed flowers drop off the cluster, which is called shatter.
What is millerandage?
POOR OR IRREGULAR FRUIT SET: some grapes forming w/o seeds or remaining small due to cold, cloudy, rainy conditions during polination.
What vineyard work is done while the vine is dormant?
WINTER PRUNING: remove last year’s shoots and cane(s)
What detrimental effect can drought have on a vine?
WATER STRESS:
Vines may stop transpiration and photosynthesis,
Leaves wilt, causing grapes not to ripen,
Drought can kill a vine.
What are the effects on a vine if its roots are generally around too much water (read: poor drainage, waterlogging, etc.)?
If roots become waterlogged or have excessive water available:
- CANOPY OVERGROWTH with takes energy away from the grapes which won’t ripen properly
- BLOATED GRAPES which dilutes flavors
- ROOTS CAN ROT.
What sorts of damage can rainfall cause before, during, and after berry development?
Before: disturb flowering and fruit set
During: encourage the dvt of fungal diseases
After: if right before harvest, rain can bloat berries, dilute their juice and introducing grey rot.
What are the 3 most important irrigation systems used around the world?
DRIP IRRIGATION
SPIRNKLERS (can also be used for frost protection)
FLOOD IRRIGATION
Between clay, sand, and stone, which soil has the highest water retention?
Clay has the highest water retention and the smallest particles.
Stony and sand soils drain easily.
Besides clay, what soil element is known for good water retention?
HULUS which is organic matter made up of decomposing plant and animal materials.
What is the composition of loam soil?
Mixture of SAND and CLAY. Good water drainage and retention due to its compodition.
How many years after first planting a new vineyard will vines produce a usable crop?
3rd year after planting
How often is a vineyard typically replanted?
Every 30-50 years.
After 25-30y, a vine produces less quantity but hif=gher qulity grapes.
Is it common practice to leave a vineyard fallow for a few years after its vines have been uprooted?
YES, for 3 years prior to replanting. This allows the farmer to work the soil and help it regain its nutrients so it can accept new plantings.
What are the advantages of mechanical harvesting?
FAST
EFFICIENT: berries are shaken from stems so no need for a destemmer
LESS COSTLY (lower numer of laborers)
CAN BE DONE OVERNIGHT which saves time and costs on lowering grapes’ temperatures prior to processing them.
What are the disadvantages for mechanical harvesting?
Not selective.
Can only be used on flat lands or gentle slopes.
Not suited for all grapes: best for those that come away easily from their stems.
What are the advantages of hand harvesting?
EASIER TO CONTROL GRAPE QUALITY
Usually LESS GRAPE DAMAGE then fewer oxydation issues
Whole clusters are picked which keeps STEMS INTACT.
In some areas, hand picking is the only option eg Mosel, Valtellina, Northern Rhone
What are the disadvantages of hand harvesting?
Slow (slower than machine harvesting)
Costly because more labor intensive
What is the tool used by hand harvesters?
A pair od SECTEURS or pruning shears
What happens in the vine during early shoot + leaf growth?
RAPID GROWTH: vines use over-wintered carbohydrates to grow leaves, shoots and tendrils quickly;
Ones leaves mature enough, they take over as the engine to fuel the plant for photosynthesis.
